1. Field of the Invention
The present invention is in the water purifying and disinfecting field.
2. Description of the Background Art
U.S. Pat. No. 4,298,475 discloses an apparatus of which the tubular plastics housing accommodates an inlet-end stage of porous material, a further stage having a polyhalide anion exchange resin layer, an intermediate filter of porous polymer, an outlet filter of porous polymer and a mouthpiece. Owing to this construction, sewage water is sufficiently disinfected from microorganisms and mechanical impurities are removed to a certain extent. If, using the known apparatus, for example, river water having an initial enteric bacteria contamination of 10.sup.5 microbe cells/liter and having a content of mechanical impurities of from 60 to 100 mg/liter is sucked up continuously, the water leaving the outlet end has a contamination of enteric bacteria of from 10 to 100 microbe cells/liter and a content of mechanical impurities of from 40 to 70 mg/liter.
Those values are inadequate. In addition, the amount of water that can flow through the housing is small when the water contains a large amount of impurities of organic and inorganic origin. The average amount of water which can be taken up using such an apparatus is not more than from 10 to 15 l. The known apparatus must then be discarded.
U.S. Pat. No. 4,995,976 discloses an apparatus having a tubular housing of polycarbonate in the case of which the inlet-end stage is formed by an inlet filter which is produced from porous plastics material having a pore size of 80 .mu.m and which is placed on the inlet end of the housing. A purification stage which is formed by a purifying resin and which is used to kill bacteria, organic materials and organisms adjoins the inlet-end stage. The next stage contains activated charcoal for absorption. Finally, a sterilisation stage is provided. The individual stages are separated from one another by porous spacer discs. A respective layer of resilient foam having a larger pore size than the inlet filter or the spacer discs is provided on the front and the rear end of the activated charcoal layer.
This apparatus is able to provide purification and disinfection of water improved by one order of magnitude compared with the apparatus known from U.S. Pat. No. 4,298,475. The total amount of water which can be purified using this apparatus is, however, not greater.